Receptacle for attachment plug caps



` `May 12, 1936. c. rT voN HoLTz 2,040,113

RECEPTACLE FOR ATTACHMENT PLUG CAPS Filed Nov. 25l 195s A Tw@ .dh

fue

cap is so secured Patented May 12, 193s N UNITED .,-STAT'ES `iuioiar'rliCLE Fo 'PLUGCAPS` l Charles Theodore Von Holtz,

assignor to Harvey PATENT OF-FICE f R ATTACHMENT f' Bridgeport,` Conn., Hubbell, Incorporated,

i Bridgeport, Conn. a corporation of Connecticut Application November 25, 1933, SerialNo. 699,765

17 claims. (01173-330) This invention relates to new and useful im-j provements in receptacles for attachment plug cap are clamped or locked to prevent casual with-` drawal of the cap from the receptacle, and the withthe blades in engagement `with the contacts of the receptacle.

Another object is to provide a receptacle as stated and wherein a good electrical connection is maintained between the contacts ofthe receptacle and the contact blades of the attachment plug cap during such turning movement of the cap to prevent arcing and burning ofthecon tacts.

cluding improved contacts and improved mounting means for such contacts.

An additional object is to provide a receptacle as stated and wherein on the blades of a cap i receptacle and the cap` the usual openings in the contact blades of 'the cap to secure ,the cap and receptacle together against casual separation.

The device comprises broadly providing `a re- `ceptacle including a body of insulating material, a plug` ofv insulating material in and turnable relative to said body, a pair of contact members carried by said plug and between which and the plug the contact blades of a cap are tobe received, said plug adapted to be turned by a cap having its blades received as stated, and means whereby as said plug is turned in one direction lsaid contact members `are forced against a the blades of the cap to secure the cap and receptacle together against casual separation.

More specifically, the device comprises a` receptacle including a body of insulating material, a plug in said body,

. by said body, said plug carried contact and plug adapted to receive a contact blade of a cap between them, said plugturnablein said body, one,-

tive to'said body to cause the said cam face of one receptacle and the Another object is to provideareceptacle in? a pair `of contact members `of which one is carried by said plug and the other of saidcontact 'members to engage the other contact member and force the body carried contact against a wall of a body and force the plug carried contact against the cap blade receivedbetween it 'and the plug whereby to secure the capj against casual separation from the plug.

Other objectsand advantageswlll become ap,I

parent from a'consideration of the following de-` tailed description taken in connection withthe accompanying drawing wherein asatisfactory embodiment of the invention is shown. However,

it will be understood that the invention vis not limited to the details, disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims.

In thedrawing: n

Fig. 1 is a top'plan view'showing a duplex receptacle constructed according to the present invention;

Fig. 2 is a side elevational view thereof, parts being broken away;

Fig. 3 is a bottom plan view thereof, parts being broken away;

Fig. 4 is a sectional view on scale taken substantially along the line `44 of Fig. 2;A

a somewhat larger Fig. 5 isa sectionalview on the same scale as Fig. 4 taken substantially along the line 5-5 `of Fig. 2 and showing the body of the cap in elevation; "I i Fig. 6 is a view somewhat similar to Fig.` 4 but showing thepositions of the parts when a cap is `secured or locked to the receptacle; a l

Fig. 7 is a detail section view taken substantially along theline 'l--l of Fig. 3;

Fig. 8 is a sideelevational ing part of the receptacle; Y

Fig. 9 is a top plan view of saldplug;

Fig. l0 is a bottom plan view thereof;

Fig. 11 is a sectional view through a portion view of a. plug form# of the receptacle, the plug and contactsbeing omitted; n y A Fig. 12 is a sideelevational view of a body carried contact member of the receptacle with one binding screw omitted;y

Fig. 13 is a side elevational View of a plug carried contact member ofthe receptacle;

Fig. 14 isa top plan View of the contacto! Fig.l.3; i n., A

Fig. `15 is a section similar to one-half of Fig. 5 showing a slight modification; and

Fig. 16 isa detail section showing means ior` clearly shown in Figs.' 3

improved receptacle includes a. body I5 of insulating material having a pair of spaced openings I6 therethrough, the said openings being duplicates of one another and both being provided since the body is that of a duplex receptacle.

'I'he openings I6 are provided through ehe larged end portions of the body` and such end portions are' connected by an intermediate or bridge portion |1 which at its lower side carries a portion I8 somewhat in the shape of a cross (see Fig. 3) and providing side entrances I9 to the openings I6. Adjacent each of said side entrances the bridge or connecting piece at its under side is provided with recesses 20 the purpose of which will later appear.

Similar contact members 2|, one of which is shown alone in Fig. 12, o-ne omitted, are employed and each includes a body portion22 and end contact portions23 and 24 respectively, the former being: bent slightly inwardly out of the plane of the body portion 22 and the latter being transversely curved and connected to the body portion by'an inwardly offset portion 25. Inwardly of its end portions 23 and 24 the b ody of each contact member 2| carries a pair of finger portions 26 at one side of the body and the edges of these finger portions are provided with teeth 26a. Between the nger portions there is arranged a metal plate 21V having tapped openings therein through which are threaded the Shanks of binding screws 28. y

'Ihe contact members 2| are duplicates of one another and are of such length that while one of theirv end portionsis disposed in one opening I6 their other end portion is disposed in the other opening I6. Members 2| are mounted by inserting their finger portions 26 intothe slots or recesses 20 above referred to and their end contact portions are then disposed in the respective opening I6 inA relation to the walls of such openings as and 4. The fingers 26 of the contact members are slightly Wider than the recesses 2|] so that as the ngers are forced into the recesses the ends-of the teeth 26a dig into the material of the body I5 as shown in'Fig. 16

I and effectively lock or secure the contacts against withdrawal from the recesses. The contact members adjacent said fingers, engage the walls of the body I 5. as at the points 29, with the end contact portions 23 and 24 of the members in spaced relation to said walls of the body whereby said end contact portions may be flexed as will later appear. It will be noted the two contacts 2| are reversed with respect to each other so that the end portion 23 of one contact is at one side of an opening I6 and the portion. 24 of the other contact is at the opposite side of the vsame opening I6.

Openings I6 are of greater diameter at their inner thanV at their forward or front ends whereby a. limiting shoulder 30 is formed within each opening inwardly of its forward end. Arranged in each opening I6 is a plug 3| of insulating material and each plug comprises an elongated body -of a diameter in one direction substantially equal to the diameter of the opening I6, the said body being flattened on its outer sides measured across its other diameter. In these flattened sides the plugs vare provided with 'grooves 32 opening through the outer or forward end 33 of the plugs. Adjacent the inner ends of the plug a bridge piece 34 is provided across each ofthe grooves and in its inner end each plug is providedwith a pair of Tashaped depressions 35 extending through the attened -sides of the plug.

binding screw being Each plug 3| carries a pair of contact members 36 each including an arm or prong 31 and an angularly related T-shaped arm or head 38. 'I'hese contact members 36 are disposed one at each side of the plug with their heads 38 arranged in the depressions 35 in the inner end of the plug and with their arms 31 arranged .over Vthe grooves or slots 32 in thesides of the plug. The contacts are capable of a slight rocking movement owing to their engagement with the bridge pieces 34 whereby the free end portions of the arms 31 of the contacts may be tilted into and out of the grooves 32. Plug 31 is of two diameters whereby it includes a shoulder 39 to engage With the shoulder 30 before referred to.

As above stated, the openings I6 extend entirely through the body I5 of the receptacle and in assembling the receptacle the contact members 2| are pushed into place as above explained. Next, the plugs 3| with the contact members 36 assembled on them are inserted into the openings I6 in the positions as best shown in Figs. 3 and 4 with the arms 31 of the contact members 36 engaging the co-ntact portions 23 and 24 of a pair of the contact members 2|. When the plugs are inserted the proper distance into the opening I6 the shoulders 39 of the plugs will engage the shoulders 3U in the opening and movement of the plugs outwardly through the front or forward end of the receptacle will be prevented.

A sheet or strip 40 of insulating material is disposed over the inner end of the receptacle and then a mounting strap 4| of any or the usual construction is applied. This strap 4| is substantially U-shaped and includes a connecting portion 42 disposed against the outer surface of the strip 40 and includes arms 43 disposed one at each -side or end of the receptacle and entering into recesses 44 provided for their reception in the lower walls of the overhanging portions 44a of the body I5. These recesses lock the end portions of the yoke onstrap 42 against movement outwardly away from the body I5. The end portions of these arms are turned outwardly to provide attaching'ears 45 by means of which the receptacle may be mounted in an outlet box. The intermediate portion 42 of the mounting strap 4| carries a rivet 46 extending through the body I5 and at its upper or outer end threaded as at 46 for the reception of the shank of a screw used to secure in place a flush or wall face plate (not shown).

It will be noted that on its outer surface beginning at one longitudinal edge each of the arms 31 of the contact members 36 are curved or beveled to provide a cam surface 41 and that the free end of each of said arms is tapered or cut away on its inner side as at 49. The cam surface 41 may be an arc struck from a center 41a offset to one side of the center 0n axis 3|a of the plug 3 I. When the parts are all assembled the contact blades 50 of an attachment plug cap 5| may be inserted through the outer open ends of the grooves 32, the said blades occupying the grooves and forcing the arms 31 of contact members 36 outwardly with respect to the grooves. 'I'he outer or forward ends of the plugs 3| are arranged ush or substantially flush with the outer or forward surface of the enlarged portions of the body I5.

Since the ends of the arms 31 are beveled as at 49 it is apparent that the contact blades 59 may be easily inserted into the grooves 32 between the plug and the said arms 31. Lead wires of the house wiring system are attached to a pair of the binding screws ,28 at opposite sides of the body l and the other pair of binding screws may be connected byjmeans of leads with another receptacle or the like. The contact members 36 through their aims 31 are always in en-y gagement with the contact portions 23 vand 24 of the contact member 2| and thereforewhen the blades 50 are inserted into the grooves 32 they engage live contacts., This engagement results from the fact that the contact portions23 and 24 are resilient and normally tend to 'move inwardly to press against the arms 31 and so serve Vto press said arms 31 against the contact blades 50. The blades of the cap may normally be inserted and removed in the usual manner when the plug 3| is in the position of Figs. 1, 3, and 4, as in this position the spring contact portions 23 and 24 are spaced inwardly a short distance from the walls 54a of the body I5 so that they and the contacts 36 are'free to yield outwardly as the blades 50 are inserted between the contacts 36 and the bottoms of the grooves 32. s

When the contact blades 50 have been inserted into the receptacle as above described the cap 5| may be secured to the receptacle if desired. To accomplish this it is but necessary to give the cap a slight rotary movement to the right" or clockwise as viewed in Fig. 4 or to the left or counter lclockwise as viewed in Fig. 3, and such movement will shift the plug and contact members carried by it from the positions in which they are shown in Figs. 3 and 4 to that `in which they are shown in Fig. 6. In Figs. 3and'4 it will be noted that the contact portions 23 and 24 of `contact mem-l` bers 2| are spaced `from the adjacent Walls 54a of the opening I6 land it will benoted ,that such contact portions are in engagement with/the inclined or cam surfaces 41 of the contact members 36.. 4

VOn turning of the plug 3| its contact members 36 are shifted and their cam surfaces ride against the end portions 23 and 24 of contact members 2| and force such portions against the adjacent walls 54a of the opening |6 in the manner clearly shown in Fig. 6. The arms 31 ofthe contact members 36 are thus forced or clamped against the inserted contact blades 50 and if desired each of these arms may be provided with an inwardly pressed lug 52 which when the parts are shifted vided in the contact blades.

Since the contact end portions 23 and 24 may not yield outwardly any farther the arms 31 of the contact members 36 are held in rm engagement with the contact blades 5|)` and the lugs 52 `are held in the openings 53` in such blades.

Therefore, the bladesmay not beeasily pulled out of the receptacle and the receptacle and cap are held or locked against casual separation. On the cap being given a turning movement in a reverse direction the parts are returned to normal position and the cap may be removed and applied in the usual manner. Within the body the opening I6 at opposite sides is cut laterally to provide recesses 54 receiving the different contact members. s

If it is notdesired that the blades 5|) be locked in the receptacle but 'merely be held by increased friction thenk the lugs52 may be omitted from the contacts 36 as shown in Fig. l5. kWith this arrangement the contacts are .clamped when `the plug 3| is turned to the position of Fig. 6 but are not positively locked. That is, they are clampedV ^and held by increased friction so that, they are much more ilrmly held and it is more difllcult to withdraw them from the receptacle than normally, but if there is an excessive pull on the lead wires 5|c connected to the cap then the blades 50 may be pulled from the receptacle without breaking the leads or other parts.

Whereithe term standard" cap is used in the specification and claims this is intended to mean a cap having two projecting contact blades parallel to each other of substantially rectangular cross section of substantially uniform width and thickness throughout at least the portions intended to engage the contacts of receptacles and connectors except for a transverse opening through them adjacent their ends. In other Words these are the connector caps having contact blades of the size, shape and arrangement which is standard electrical practice at the present ing or securing the cap to the receptacle and therefore the device used in the usual manner, and if desired, by a slight turning movement of the cap after it is applied it may be secured to the receptacle .against casual separation. Just as soon as the blades of the cap engage the arms 31 of the contact members 36 an electrical connection is established and this connection is unbroken during further insertion of the blades into the receptacle and is not broken by a turning of the cap so as to lock or secure it to the receptacle or by a turning movement to unlock the cap.- Therefore, there will be no arcing Within the receptacle such as would occur should the electrical connection with the `contact blades be made or broken during turning movementv of the cap to locking or released position.

It will also be noted that the device includes only relatively few parts each of which may be strongly constructed and that the contact members 2| and 36 maybe easily and quickly assembled in the body and on the plug respectively and the plug may be easily assembled in the body. The plug ls held against movement through the forward end of the body by engage-` ment of its shoulders 39 with the shoulders 30 Within the opening I6 and the insulating strip v4|) together with the strap 4| serve to prevent movement of the plugs and the contact members carried by them through the rear end of the body.`

s vention, what I claim is:

`1. In a receptacle, abody of insulating material, contacts in said body to be engaged by the straight parallel contact blades cf a standard attachment plug cap, and means whereby on the blades of a standard cap being inserted into said receptacle in their normal parallel relation and said cap given a partial turn without moving the blades from their normal positions, means is forced against one of the blades of the cap to frictionally secure the vcap to the receptacle.

2. In a receptacle, a body of insulating material, contacts in said body to be engaged by the straight parallel contact blades of a standard attachment plug cap having openings therein, and means whereby on the blades of a standard cap being inserted into said receptacle in their normal parallel relation and said cap given 'a partial turn without moving the blades from their normal positions means is forced into the opening in one of the blades of the cap to secure the cap to the receptacle.

3. In a receptacle, a body of insulatingmateriai, a plug of insulating material in and turnable relative to said body, a pair of contact members carried by said plug and between which and said plug the blades of an attachment plug cap are adapted to be received with said blades in engagement with said contact memberssaid plug adapted to be turned by the turning of a cap having its blades in the receptacle as stated, and mea-ns whereby as said plug is turned in one direction its contact members are forced against the blades of the cap to secure the cap and receptacle together.

4. In a receptacle, a body of insulating material, a plug of insulating material in and turnable relative to said body, a pair of contact members carried by said plug and betweiijvhich and said plug the blades of an attachment plug cap are to be received with said blades in engagement with said contact members, alug on one of said contact members, said plug 'adapted to be turned by the turning of a cap having its blades received in said receptacle as stated, and means whereby as said plug is turned the lug carrying contact member is held against movement away from the cap contact blade with which it is in engagement and said lug is held in an opening in said blade to secure the cap and receptacle together against casual separation.

5. In a receptacle, a body of insulating material, a plug of insulating material in and turnable relative to said body, a pair of contact members carried by said plug and between which and said plug the blades of an attachment plug cap are to be received with said blades in engagement with said contact members, a pair of contact members in said body and in engagement with said contact members carried by the plug, one of said pairs of contact members having cam surfaces, said plug adapted to be turned in said body by turning of a cap having its contact blades received as stated, and said cam surfaces of one of saidpairs of contact members adapted to coact with the other pair of Contact members on the turning of said plug whereby to force the plug carried contact members into tight frictional engagement with the contact blades of the cap.

' 6. In a receptacle, a body of insulating mate rial-. a plug of insulating material in and turn- -ablegrelative to said body, a pair of contact mem bers'carried by said plug and between which and said plug the blades of an attachment plug cap are adapted to be received with said blades in engagement with the contact members, a lug on one of said contact members, a pair of contact members in said body and in engagement with said contact members carried by the plug, one of said pair of contact members having cam surlaces, said plug adapted to be turned infsaid body by turning of a cap having its lcontact blades received as stated, and said cam surfaces of one of said pair of contact members adapted to coact with' the other pair of contact members onA the turning of said plug whereby to force the plug carried `contact members against the contact blades of the cap with the said lug on one of the plug carried contact members located in an opening in one of the contact blades of the cap.

'7. In a receptacle, a body of insulating material, a plug of insulating material in and turnable relative to saidbody, a pair of contact members carried by said plug and between which and said plug the blades of an attachment plug cap are to be received with said blades in engagement with said contact members, said plug adapted to be turned by the turning of a cap having its blades in the receptacle as stated and while said contact blades are in engagement with said contact members, and means 'whereby as said plug is turned in one direction its contact members are forced against the blades of the cap to secure the cap and receptacle together.

8. A receptacle including la body of insulating material, a plug of insulating material in said body, a pair of engaging contact members of which one is carried by said plug and the other by said body, said plug and contact member carried thereby adapted to receive a contact blade of an attachment plug cap between them with the blade and contact member in engagement, said plug turnable in said body, one of said body and plug carried contact members including a cam surface, and said plug when a cap is plugged into the body and turned adapted to turn with said cap and cause the cam face of one of said contact members to ride against the other thereof and force the body carried contact member against a wall of the body and force the plug carried contact member against the cap blade received between it and the plug whereby to secure the cap and receptacle together against casual separation.

9. A receptacle including a body of insulating material, a plug of insulating material in said body, a pair of contact members carried by said body, a pair of contact members carried by said plug and engaging the contact members of the body, said plug and contact members carried thereby adapted to receive the contact blades of an attachment plug cap between them with the blades and contact members in engagement, said plug turnable in said body without disengaging any of said contacts, one of said pairs of contacts including cam surfaces, and said plug when a cap is plugged into the body and turned adapted to turn with said cap and cause the cam faces of one of said pairs of contact members to ride against the other contact members and thereby force the body carried contact members against walls of the body and force the plug carried contact members against the cap blades whereby to 'secure the cap and receptacle together against casual separation.

10. A receptacle including a body of insulating material, a plug of insulating material in said body, a pair of spring contact members carried by said body, a pair of contact members carried by said plug and engaging the contact members of the body, said plug and contact members carried thereby adapted to receive the contact blades of an attachment plug cap between them with 'the blades and contact members in engagement, said plug turnable in said body Without disengaging any of said contacts, one of said pairs of contacts including cam surfaces; and

said plug when a cap is plugged into the body and turnedadapted to turn with said cap and cause the cam faces of one of saidpairs of contact members to ride against the other contact members and thereby force the spring body carried contact members against the wall of the body and force the plug carried contact members against thecap blades whereby to secure the cap and receptacle together against casual separation.

11.l A receptacle including a body, of insulating material, a plug of insulating material in said body, a pair of engaging contact members of which one is carried by said plug and the other by said body, said plug and contact member carried thereby adapted to receive a contact blade of an attachment plug cap between' them with the. blade and contact member in engagement, said plug turnable in said body, said plug carried contact member including a lug,one of said body and plug carried contact members including a cam surface, and said plug when a cap is plugged into the body andturned `adapted to turn with said cap and cause the cam face of one of said contact members to ride against the other thereof and force the body carried contact member against a wall of the body and hold the plug carried member against movement away plug carried contact member against movement away from the cap blade with the lug of said member in an openingin said blade whereby to secure the cap and receptacle together against casual separation. l

12. In a receptacle, a body of insulating material, said body havingan opening therethrough of two diameterswhereby a shoulder is formed, a pair of contact members carried by said body and entering said opening, a plug of insulating material in said opening and having a shoulder engaging the rst mentioned shoulder, means across one end of said body and maintaining the shoulder of the plug in engagement with' the shoulder of the body whereby the plug may not be casually withdrawn from the body, said plug 5 rotatable in said opening, a pair of contact members carried by said plug and engaging the body carried contact members, said plug carried con- \ta ct members and said plug adapted to receive the contact blades of a cap between them, and

means whereby onturning of said plug while the blades of a cap are so received the body and plug carried contact members wedge against one another and the plug carried contact members are forced against the contact blades of the cap to secure the cap and receptacle together against casualseparation.

13. In a receptacle, a body of insulating material, said body having an opening therethrough of two diameters whereby a shoulder is formed, a 00 pair of `contact members carried by said body and entering said opening, a plug of insulating material in said opening and having'a shoulder engaging the rst mentioned shoulder. means across one end of said body and maintaining the shoulder of the plug in engagement with the shoulder of the body whereby the plug may not be n casually withdrawn from the body, said plug` rotatable in said opening, a pair of contact members carried by said plug and engaging the body carried contact members, said plug carried contact membersand said plug adapted to receive the contact blades oi a cap between them, and means whereby on turning of said plug while the blades of a cap are so received the plug carried contact members are forced against the contact blades of the cap to secure the cap and receptacle together against casual separation.

14. In a receptacle, a body'of insulating material, a plug of insulating material in and turnable relative to said body, said plug having a pair of grooves in its outer side walls and a pair of T- shaped depressions in its lower end wall communicating with said grooves, contact members carried by said plug, each of said contact members including a portion over-lying one of said grooves and an angularly disposed T-shaped end portion disposed in one of said T-shaped recesses. said plug adapted to have the blades of an attachment 'plug cap inserted into said grooves beneath and in engagement with said contact members, a pair ofcontact members in said body and in engagement with said plug carried contact members, said plug adapted to be turned in said body by turning of a cap having its blades received in said grooves, and means whereby as said plug is thus turned the plug carried contacts are forced against the blades of the attachment plug cap to secure the cap and receptacle together against casual separation.

n 15. In a receptacle, a body of insulating material, a plug of insulating material in and turnable relative to saidbody, said plug-having a pair of grooves in its outer side walls, contact members carried by said plug, each of said contact members including a portion over-lying one of said grooves, said plug adapted to have the blades of an attachment plug cap inserted into said grooves beneath and in engagement with said contact members, a pair of contact members in said body and in engagement with said plug carried contact members, said plug' adapted to be turned in said body by turning of a cap having its blades received in said grooves, and means whereby as said plug is turned the plug carried contacts are forced against the blades` of the attachment plug cap to secure the cap and receptacle together against casual separation.

16. In a receptacle, a body of insulatingmaterial, a plug of insulating material in and turnable relative to said body and having a pair of spaced Openings to receive the blades of an attachment plug cap, apair of contacts carried by said plug, said plug adapted to be turned relative to the body by the turning of a cap having its blades in said openings, and means whereby as said plug is turned in one direction its contacts'are forced against the blades of the cap to secure the cap and receptacle together.

17. In a receptacle, a body of insulating material, a plug oi! insulating material in and turnable relative to said body and having a pair of spaced openings to receive the blades of an attachment plug cap, a pair of contacts carried by said plug, a lug on one of said contacts, said plug adapted to be turned relative to the body by the turning of a cap having its blades in said openings, and means whereby as said plug is turned in4 one direction its contacts are forced against the blades of the cap and said lug is held in an opening in one of the blades to secure the cap and receptacle together against casual separation.

CHARLES THEODORE VON HOLTZ. 

